This application claims the benefit of a Japanese Patent Application No. 2004-253110 filed Aug. 31, 2004, in the Japanese Patent Office, the disclosure of which is hereby incorporated by reference.
1. Field of the Invention
The present invention generally relates to power supply control methods, power supply control units and information processing apparatuses, and more particularly to a power supply control method using an uninterruptible power supply (UPS), a power supply control unit and an information processing apparatus that are used with an UPS.
2. Description of the Related Art
Depending on the usage of an information processing apparatus such as a general-purpose computer, the information processing apparatus is in a state connected to an uninterruptible power supply (UPS), so that the information processing apparatus can continue to operate even when a supply from an A.C. power supply stops due to a power failure or the like. The UPS is connected to the A.C. power supply. During normal operation, the information processing apparatus operates based on a power supply voltage that is supplied from the A.C. power supply via the UPS. When the supply of the power supply voltage from the A.C. power supply stops due to a power failure or the like, the UPS detects this abnormality and automatically supplies a power supply voltage from a battery or the like to the information processing apparatus, in place of the A.C. power supply. As a result, the information processing apparatus can continue to operate even when the abnormality such as the power failure occurs.
Some information processing apparatuses are provided with a schedule setting application that manages a schedule with which the supply of the power supply voltage is to be turned ON and cut OFF. When ON/OFF time information related to dates and times for turning ON and cutting OFF the supply of the power supply voltage is set to the schedule setting application, the ON/OFF time information is supplied to the UPS, and the UPS controls the ON/OFF of the supply of the power supply voltage to the information processing apparatus based on the ON/OFF time information.
However, the supply of the power supply voltage may not made based on the ON/OFF time information if a failure of the information processing apparatus and/or a failure of the UPS occur. For example, even though the schedule for turning ON the supply of the power supply voltage to the information processing apparatus at a certain date and time has been set to the schedule setting application, the supply of the power supply voltage to the information processing apparatus may not occur at the certain date and time. In such a case, an operator of the information processing apparatus must investigate the cause, that is, why the supply of the power supply voltage did not occur at the certain date and time, and attend to the repair of the failure. But when investigating the cause, the operator must first determine whether the failure occurred in the information processing apparatus or in the UPS, before detecting the actual location of the failure within the information processing apparatus or UPS, and then attend to the actual repair of the failure. Consequently, an extremely troublesome and time-consuming operation was required to restore the information processing apparatus and also the UPS if applicable. In addition, the reliability of the information processing apparatus deteriorated due to the time-consuming restoration operation.